The aim of the proposed project is to elucidate the molecular mechanism of gene action in man through biochemical approach. The project consists of the following studies: (1) Determination of complete amino acid sequence of normal human glucose-6-phosphate dehydrogenase and phosphoglycerate kinase, and elucidation of amino acid substitutions of variant enzymes. Because of the existence of structural variants associated with abnormal enzymatic properties and hemolytic disorders, these studies, together with the three dimensional structure of the enzymes, molecular pathology of these enzyme abnormalities will be advanced. Screening and characterization of new variant enzymes will be carried out. (2) Determination of complete amino acid and carbohydrate sequence of normal alpha 1-antitrypsin (A1AT). Amino acid substitution and carbohydrate abnormality of variants A1AT will be undertaken. The basic knowledge obtained by the studies may lead to understanding of A1AT abnormalities associated with emphysema. (3) Purification and characterization of carbohydrate transferases involved in synthesis of blood group substances. Two transferases, i.e., N-acetylgalactosaminyltransferase, and galactosyltransferase were recently purified to homogeneity in this laboratory. Studies of structure and immunologic homology of the two enzymes and other transferases in human blood will lead to understanding of underlying genetic mechanims of expression of blood types. (4) Determination of amino acid sequence of human embryonic hemoglobin epsilon chain. (5) Purification and characterization of the enzymes related to genetic disorders.